having unequal length axles would have very little to no effect on the AWD system, it still divides torque equally.
Subaru uses a viscous diff, audi uses a torsen diff. torsen not only reacts faster, it transfers torque more effectively, and it transfers torque before the wheel totally slips. in pretty much all cases, audi's AWD is superior.
subaru also relies more on electronics, while audis AWD system is mostly mechanical.
Audi not only wins on paper, but when it comes to actually performing on snow they also win. ive driven a bunch of subaru's on snow, and their tendancy to understeer in the dry only gets much worse in the snow. where while audi's tend to understeer in the dry, they have very neutral handling characteristics in the snow. partly due to their weight distribution in general being better suited for snow, and partly because of their surperior AWD system.
actually the best AWD car ive driven is an E30 e25ix, its AWD system on paper is supposed to be worse than audi. but the way the car is set up allows it to handle very neutral, it has a ton of grip on turn in, and the torque split gives a little more torque to the rear which seems to work better than 50/50, since the car squatting under acceleration gives the rear more grip.
but id still like to drive an old UR quattro or 90, i could see those doing amazingly well in snow.
Both companies have a lot of variations in their different models, but this is all true for the most part. some of the newer audi's and subaru's have complex electronics and traction control type crap in their AWD systems and i dont even want to start getting into that, because for the most part they are shit.
